Artificial leg.



J. w. 110mm & H. 'E. LA PLANT.

ARTIFICIAL LEG. APPLICATION IILED APILS, 1912.

Patented Jan. 7, 1913.

E llix ATTORN EY WITNESSES COLUMBIA PLANOURAPH (IO-,WASHINGTON, D c.

' I The present inventi position, which can be readily adjusted to.

, UNITED STATES PAT NT OFFICE. i

JAMES wfrioncn nn HARRY EULA PLANT, or KENNETT, CALIFORNIA.

1 ARTIFICIAL LEG.

Specification of Letters Patent.

I Application filed April 3, 1912. Serial No. 688,126.

To all whom it may concern: I

Be it known that we, JAMES W. Honor: and HARRY E. LA PLANT, citizens ofthe United States, residing at Kennett, inythe county of Shasta andState of California, have invented new and useful Improvements inArtificial Legs, of which the following.

is a specification. V

'on relates to improvements in artificial legs.

The object of the present invention is to provide an artificialleghaving great freedom of movement at the. ankle andhaving a knee andankle action very closely resembling that of thennatural leg, one whichwill be extremely free from ar in walking, one which will support withgreat comfort and ease the wearer when in a standing variations inweight of the wearer, and which will permit of easy ascent or descent,both on fiat surfaces as stairs, and on slop,- ing ground.

In the accompanying drawing, Figure 1 is a-vertical sectional, view ofour improved artificial leg; Fig. 2 is a perspective v ew of a guideway'detached; Fig. 3 is a crossupper portion of the device, which isattached to the stump of theyleg, are here "omitted, being of theusualconstruction.

. 1 indicates the "casing of the intermediate portion of the :leg, madeof any suitable material, and having secured. at the top thereof thehinge straps 2 for attachment to the upper portion of the artificialleg. Within said casing 1 is a guideway 3 formed of a single piece ofsteel'bent so as to form a central member 4:, screwed as shown at 6, tothe front portion of the casing and parallel side members 7 extendingfrom said central member, and bent outwardly at their terminal portions8 to fit snugly against the inner rear surface of the casing 1 and "'secured thereto by screws 9. Said members 7 thus form a guideway, in whichcan slide a rectangular nut 11 screwed ona stem 12,

threaded at its upper portion throughout;

the greater part of its length. Also on said threaded portion 'of'thestein, one oneach side of the nut 11, are sleeves l3, screwed tightlyup. against the upper and. lower ends of said nut respectively, for thepurpose of furnishing smooth interior guides for up per and lower coiledsprings 14,16, which surround the sleeve andstem and are compressedbetween washers 17 around the sleeves .13'and terminal washers 18. The

terminal washers are held in place by upper andlowernuts19,screwed onsaid stem, and

PatentedJanQT,1913.

the; washers 17 aresupported against the I spring pressure, by means ofrubber rings '21 interposed betweensaid washers and the upper andloweredges respectively ofrthe side members of the guideway, said sidemembers being, at the parts adj acent' to said" rings, formed withoutwardly extending flanges 22, against which said rubber ringsres't,1so that the cutting of the rubber is avoided. I

23 indicates the foot portion of the artificial leg, hinged inthe usualmanner, as

shown at 24,v to the casing 1. The heel of sa d foot is recessed, asshown at 26,and in sa d recessis a transversely extending pivot 27,-whichpasses through a bearing. 28-

formed on thelower end of the stem 12.

The advantages of our invention will now be readily apparent. In thefirst place, the

upper and lower springs [assist the wearer the erect position isresisted by the pressure of the upper spring, which, bysaidbending inmaintaining a standing. position, for any movement, would be compressed,and in like manner; ajrearward movement is resisted by the lower spring.It will be observed that, when either spring is thus called into'action, the other spring has no effect whatever. .For instance, iftheleg be bent forward, then the stem12 is drawn down, which has the effectof compressing the upper spring 14:betweenthe upper, washers 18, 17,

but thelower spring is, bysaid downward 'movementof the stem, not causedto expand for the nut 11 movesfdownwardwith the stem, and thus the lowerspring is compressed equally as before between the lower washers 18, 17.

- 'Itwill readily be seenvthat, with this construction ample angularmovement of; the Y ankle inwalkingispossible, and, if the foot beresting on the ground, the lower part of the leg can be moved through avery wide angle relatively to the foot, and therefore also the knee canbe bentthrough avery 1 wide angle.

their normal position. For, in walking for- After each such bending, thef upper spring assists in restoring parts to n a Ward, the foot being onthe ground and the casing 1 being bent in a forwardly direction,

said upper spring 14 is compressed. .This

compression of said upper spring continues foot upon the ground again inthe forward position, the lower spring 16 is first compressed, and theexpansion of this spring then not only act-s as a cushion in preventingthe jar upon the body when coming in contact with the ground, but itaids the body in passing to the front of the artificial leg which is atthis time on the ground.

' On account of the large amplitude of angular movement which ispermissible to the foot relatively to the casing 1, this artificial legis particularly adapted for ascending and descending, both on flatsurfaces as stairs, and on sloping surfaces asthe side of a hill.

By adjusting the nuts 11 and 19 to vary thepressures of the springs, theleg can be perfectly adapted to support the weight of the wearer.

While the washers 17 and rings 21 serve to increase the resiliency anddurability of the device, it will readily appear that the reallyessential feature of the construction is that the diameter of thesprings should be less than the length of the nut or slide piece 11, andgreater than the width of the guideway 7, so that the inner ends of saidsprings can pass outwardly from the guideway with the nuts, but cannotpass through the guide way with said nuts.

lVe claim 1. In an artificial leg, the combination of a casing, a footportion pivotally secured thereto, a guideway secured to the said casing, a stem pivoted to the foot portion at the rear of the pivot of thelatter to the casing and passing through said guideway, abutments onsaid stem on opposite sides of the guideway, a device secured to saidstem and slidable in said guideway, and coiled springs Copies of thispatent may be obtained for five cents each, by addressing theCommissioner of Patents around said stem on opposite sides of saidguideway between said device and abutment-s, each spring being of adiameter greater than the width of said guideway, and less than thelength of said device.

2; In an artificial leg, the combination of a casing, a foot portionpivoted thereto, a

guideway secured to said casing, a threaded stem pivoted to the footportion at the rear of the pivot 0f the-latter to the casing and passingthrough said guideway, nuts screwed on said stem on opposite sides ofsaid guideway, sleeves screwed on said stem between said nuts and theguideway, washers around the stem on opposite sides of the guideway, andcoiled springs between said nuts and the washers.

3. In an artificial leg, the combination of .springs between thelast-named nuts and the washers. I

4-. In an artificial leg, the combination of a casing, a foot portionplvoted thereto, a

guideway secured to said casing, a threaded stem pivoted to the footportion at the rear of the pivot of the latter to the casing andpassingthrough said guideway, a nut screwed on said stem and slidable in saidguideway, sleeves screwed on said stem and 0 named nuts and the washers.

In testimony whereof we have hereunto set our hands in the presence oftwo subscrlblng witnesses.

JAMES W. HODGE. HARRY E. LA PLANT.

Vitnesses L. L. STILLsoN, W. GREGG.

Washington, D. G.

